What Climate Does a Lemon Tree Have to Live In?

Lemon trees need protection from frost.

Lemon tree species (Citrus limon) are subtropical: they do well in warm climates, tolerate drought and are highly sensitive to frost. They are best suited to United States Department of Agriculture hardiness zones 9 to 11. While lemon trees can live in conditions that are less than optimal, fruit production is affected. In citrus-growing regions, such as California and Florida, lemon trees need to be helped along with water and heat to ensure a full harvest.

Climate

Citrus species, including lemon trees, grow in tropical and subtropical humid regions. In the subtropics, citrus grows between sea level and 2,450 feet; in the tropics it grows at elevations below 5,250 feet. Lemon trees thrive in temperatures between 77 and 86 degrees Fahrenheit, but tolerate the high temperatures experienced in citrus regions, such as California, where temperatures can climb over 100 degrees Fahrenheit. They need full sun for fruit production, which is limited if the tree is in shade for more than six months.

Cold Tolerances

Lemon trees are limited by cold temperatures; below 55 degrees Fahrenheit the tree becomes inactive. Fruit is killed in 30 minutes when the temperature drops to 26 to 28 degrees Fahrenheit, and stems and leaves are killed in a few minutes at temperatures between 20 and 26 degrees Fahrenheit. The tree can fare better or worse at the limits of cold temperatures depending on various factors, such as the age of the fruit, leaves and branches, dryness of the air and length of the cold period.

Water

Lemon trees are sustained when the mean annual rainfall is between 35 and 120 inches. For significant fruit production lemon trees need 35 inches a year; otherwise irrigation is necessary. The tree tolerates one to three consecutive months with less than 1.6 inches of rain, though it grows in the Mediterranean, where dry seasons can last up to 4 months. Without irrigation, fruit production is reduced in drought conditions.

Strategies for Cultivating Lemon Trees

Irrigation and frost-protection measures keep lemon trees productive at the limit of their tolerances. Irrigation supplements rainfall; keeping lemon trees well-watered and healthy helps them withstand frost. Planting lemon trees at higher elevations where the air is warmer than in low spots minimizes frost damage, and fertilizing and pruning early in the season stimulates growth so the fruit has time to develop before cold weather. A full canopy has a sheltering effect for the fruit at freezing temperatures, or a light bulb can be placed in the tree to prevent frost damage.